The QLP routine removes the large-amplitude variations by applying a high-pass filter [1]}. From the bottom panel of Fig. REF , it is also apparent that residual instrumental and reduction artifacts due to imperfect background subtraction and/or poorly defined aperture might be present in the data (magenta diamonds, SPOC LC data). These artifacts appear more often in the SPOC LC data than in the SPOC SC or QLP data and can cause serious trouble in classification of variability types. In the worst case, the artifacts can lead to a completely wrong classification. The QLP routine can even fully remove the variations (Fig. REF , bottom panel). A nice comparison of the available data products and their suitability for the large-amplitude variables investigation, particularly for Cepheids and RR Lyrae stars, observed by the Kepler [2]} and TESS missions, can be found in [3]} and [4]}, respectively.
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